Failed to use Channel Sounding Mode 3

[Fhar]

Hello Support Team,

I am currently working on Channel Sounding with the nRF54L15 devkit, and I am encountering an issue when using main_mode.

Until now, I was using the default configuration BT_CONN_LE_CS_MAIN_MODE_2, and I decided to try MODE 3, as shown below:

.main_mode_type = BT_CONN_LE_CS_MAIN_MODE_3,
.sub_mode_type = BT_CONN_LE_CS_SUB_MODE_1,

I also changed the following configuration in prj.conf from n to y 

CONFIG_BT_RAS_MODE_3_SUPPORTED=y
CONFIG_BT_CTLR_SDC_CS_STEP_MODE3=y

However, after compiling, I encountered the following issues:

<err> app_main: Failed to create CS config (err -22)

Do you have any idea how to fix this? I have seen that this discussion (7 months ago) https://devzone.nordicsemi.com/f/nordic-q-a/123030/issue-with-channel-sounding-modes-on-nrf54l15dk talk about it already but wasn't answered. 

Thank you in advance for your help.

Best regards,

[SwRa]

Hi Harmel,

I see that you have added the following:

.main_mode_type = BT_CONN_LE_CS_MAIN_MODE_3,
.sub_mode_type = BT_CONN_LE_CS_SUB_MODE_1,

This is not a valid combination of main mode and sub mode types.. See here: https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-62/out/en/low-energy-controller/channel-sounding.html#UUID-5bd41abf-c6ad-a020-d3cf-e6ad8434fc66_N1690580327249 

The valid combination to run step mode 3 is as follows:

.main_mode_type = BT_CONN_LE_CS_MAIN_MODE_3,
.sub_mode_type = BT_CONN_LE_CS_SUB_MODE_UNUSED

Please see if that helps.

Best Regards,

Swathy